rotax 583 cooling system help

[xcya]

I have an older type 583 rotax engine in my poo chasie with artic cat clutches. this sled works awsome with this set up but i am puzled by the coolant hose that comes from the top of the cyl. head cover back to the coolant tank? does this need to be there or not? I have noticed that on the newer 583 engines that there is no coolant line there anymore. it also has 42 deg. c thermostat. Also is the temp. sending unit designed for an idiot lite or for a temp. gauge? Right now it's hooked up to a lite and comes on when the engine is just worming up. Thank you for any help.

 

[JBDoo]

That hose is to circulate the coolant to the resevoir and then back to the waterpump while the t-stat is closed. If you are not running a t-stat you can eliminate it but make sure to warm up your engine better before taking off or you will be looking at a 4 corner piston scuff or worse. There were sensors for lights or gauges, it sounds like you have a gauge type sensor hooked up to the light.

 

[xcya]

Thank you for the info, i was worried and didn't want to ride it. this thing should be ready to go then. the top end was just rebuilt and need to break it in now.